This invention relates to labels for containers, and more particularly to adhesive coated thin film labels.
Printed labels are widely used on containers to identify the particular products, manufacturers and brand names associated with the products in those containers. Conventional paper labels have been widely used for many years, however paper labels suffer several drawbacks, such as susceptibility to abrasion and poor adhesion in wet or moist conditions. An increasingly popular means of labeling containers has been through the use of pre-printed thin film labels. Thin film labels are made from a web of polymeric material printed with desired indica and applied to containers with an adhesive. These thin film labels provide a printed-on look to the containers to which they are applied and result in a label which is generally more durable than conventional paper labels. Thin film labels are generally die cut from the web of polymeric material to define a discrete label shape and are often provided on a web of carrier material such as a release liner.
It is desirable to make thin film labels from as thin a film as possible. Thinner films increase the aesthetic appearance of the labels, reduce overall material costs, and improve efficiency in the label application process. For example, as the thickness of the film is decreased, more labels may be supplied on a length of release liner which is to be wound into a given size roll. Conventional thin film labels generally have been made with thicknesses in the range of 2 to 3 mils, or even greater. It has long been desired to decrease the thickness of thin film labels to less than about 1 mil. However prior attempts to produce and apply labels less than about 1 mil in thickness in production environments have heretofore been unsuccessful.
While thin labels are desirable, they also create problems, particularly in the manufacture of the labels and the application of the labels to their respective containers. Very thin film labels exhibit relatively low stiffness, whereby attempts to dispense very thin film labels having a thickness of about 1 mil or less, from conventional peel tip equipment have been unsuccessful. Thinner labels also introduce durability issues into automated label application processes. Because the automated processing equipment used to package containers to which the labels will be applied are often run at high speeds, the labels must be applied to the containers at speeds which are sufficiently similar to the speed of the processing equipment. Such high speed application requirements often cause very thin film labels to stretch or split during the application process. The use of very thin films for labels stock also makes it difficult to die cut individual labels from the web of film stock without cutting through the carrier web of release liner.
There is thus a need for a very thin film label which may be applied to containers in high speed production lines, and which overcomes problems of prior art thin film labels, such as those described above.
The present invention provides a thin film label having a thickness in the range of 0.1 mil to 1.0 mil, which may be applied to substrates, such as glass or plastic bottles, or other containers. The label may be dispensed from conventional peel tip equipment to a desired container at production line speeds without damaging the label. The label may be die cut from a web of polymeric material with an adhesive on one side of the label film for bonding to the substrate.
In one aspect of the invention, multiple labels may be supplied on a web of release material for convenient dispensing in a packaging production line. It has been discovered that use of a low release value on very thin film labels will cause the labels to dispense from a peel tip when the labels have been xe2x80x9cstiffenedxe2x80x9d by applying ink in the form of graphics on the labels. The release value of the adhesive acts in conjunction with the tension and speed of the web of liner material to dispense the thin film labels to a substrate as the liner web passes over a peel tip.
In another aspect of the invention, an exemplary thin film label may be made by forming a laminate from an elongate web of thin film, a web of release liner, and adhesive disposed between the film and release liner. Visible indica are applied to the film and the film is die cut to define discrete label shapes and a matrix of waste film. The matrix is stripped from the laminate, leaving the discrete thin film labels on the web of release liner.
The features and objectives of the present invention will become more readily apparent from the following Detailed Description taken in conjunction with the accompanying drawings.